GRN and frontotemporal dementia: [27], [39] A Chinese study found that only 20% of bvFTD patients had a positive family history. [7] A preliminary study of the genetics of FTD in Indian patients did not find any pathogenic mutation in the genes encoding for microtubular associated protein tau (MAPT) or progranulin (PGRN). [40] More extensive genetic studies are in progress.